XLogCtlInsertInsert;
/* Protected byinfo_lck: */
XLogwrtRqstLogwrtRqst;
XLogwrtResultLogwrtResult;
uint32 ckptXidEpoch; /* nextXID & epoch of latest checkpoint */
TransactionIdckptXid;
XLogRecPtr asyncXactLSN; /*LSN of newest async commit/abort */
uint32 lastRemovedLog; /* latest removed/recycledXLOG segment */
uint32 lastRemovedSeg;
/* Protected byWALWriteLock: */
XLogCtlWrite Write;
/*
* These values do not change after startup,although the pointed-to pages
* and xlblocks values certainly do. Permission to read/write the pages
* and xlblocks values depends on WALInsertLockand WALWriteLock.
*/
char *pages; /* buffers forunwritten XLOG pages */
XLogRecPtr*xlblocks; /* 1st byte ptr-s +XLOG_BLCKSZ */
int XLogCacheBlck; /* highest allocated xlog buffer index */
TimeLineID ThisTimeLineID;
TimeLineID RecoveryTargetTLI;
/*
* archiveCleanupCommand is read fromrecovery.conf but needs to be in
* shared memory so that the bgwriter processcan access it.
*/
char archiveCleanupCommand[MAXPGPATH];
/*
* SharedRecoveryInProgress indicates if we'restill in crash or archive
* recovery. Protected by info_lck.
*/
bool SharedRecoveryInProgress;
/*
* SharedHotStandbyActive indicates if we'restill in crash or archive
* recovery. Protected by info_lck.
*/
bool SharedHotStandbyActive;
/*
* recoveryWakeupLatch is used to wake up thestartup process to continue
* WAL replay, if it is waiting for WAL toarrive or failover trigger file
* to appear.
*/
Latch recoveryWakeupLatch;
/*
* During recovery, we keep a copy of thelatest checkpoint record here.
* Used by the background writer when it wantsto create a restartpoint.
*
* Protected by info_lck.
*/
XLogRecPtr lastCheckPointRecPtr;
CheckPoint lastCheckPoint;
/* end+1 of the lastrecord replayed (or being replayed) */
XLogRecPtr replayEndRecPtr;
/* end+1 of the lastrecord replayed */
XLogRecPtr recoveryLastRecPtr;
/* timestamp of lastCOMMIT/ABORT record replayed (or being replayed) */
TimestampTzrecoveryLastXTime;
/* Are we requestedto pause recovery */
bool recoveryPause;
slock_t info_lck; /*locks shared variables shown above */
} XLogCtlData;
/*
* Shared state datafor XLogInsert.
*/
typedef struct XLogCtlInsert
{
XLogwrtResultLogwrtResult; /* a recent value of LogwrtResult */
XLogRecPtr PrevRecord; /*start of previously-inserted record */
int curridx; /* current block index in cache */
XLogPageHeadercurrpage; /* points to header of blockin cache */
char *currpos; /* currentinsertion point in cache */
XLogRecPtr RedoRecPtr; /*current redo point for insertions */
bool forcePageWrites; /* forcing full-page writes for PITR */
/*
* exclusiveBackup is true if a backup startedwith pg_start_backup() is
* in progress, and nonExclusiveBackups is acounter indicating the number
* of streaming base backups currently inprogress. forcePageWrites is set
* to true when either of these is non-zero.lastBackupStart is the latest
* ch